In the welding automation processes, the use of bulk containers with larger quantities of welding wire is increasingly popular since a reduction of welding wire spool changes contributes to reduce the downtime and increases the productivity and cost savings.
However, the welding wire being paid out from the container could be affected by feeding problems and tangles which would compromise the savings offered by the lesser number of spool changes.
For the control of the strands of welding wire being paid out from the container many systems have been adopted, some represented by a single element, some with more elements interacting with one another, and some made of different materials but all the solutions adopted. Examples can be found in EP 1 295 813 A2, JP 2001 026375, U.S. Pat. Nos. 5,845,862, 6,547,176, 5,277,314, 5,746,380 and 7,004,318. Even those retainers which are floating with the wire do usually not interact dynamically with the variables of welding wire coils being wound by different machines, with different adjustments, with varying sizes of welding wire and varying dimensions of the containers. The coil of wire is sometimes offset from the center of the pack and the thickness of the coil varies depending on the machine adjustment and the wire diameter.
WO 2007/112972 teaches of a combined retainer formed by a base element with openings that accommodate the holding fingers of an upper element, the holding fingers being inserted into the openings of the base element and are designed for grabbing the wire before it falls into the center of the pack. In fact most tangling is caused by strands of wire that could fall into the center of the container out of the control of the retainer, and would knot as a consequence of bad adjustment of the wire feeder rolls or tangle after catching against the conical or cylindrical core member often used in the packs.
A problem with WO 2007/112972 is represented by the variable of the coil width which is rarely consistent for a number of reasons, in particular machine adjustment, winding pattern changing with changing of wire diameter, and wire strands settling down into the container as a consequence of vibrations during handling and transport. One additional problem with WO 2007/112972 is that both the base and the upper element are made with rigid material, and the holding fingers, depending on their placement could deform the wire when they come in contact with the strand being paid from the container.
Also, if the welding wire stops shortly before the holding finger, the holding finger will oppose more resistance when the touch the wire right after the welding operation is resumed.
The object of the present invention is to provide a retainer which perfectly holds the welding wire in its proper position, even if the welding wire coil settles during transportation and for varying diameters of the welding wire coil.